The 2002 Highlander is generally solid for a first-gen Toyota crossover, but the 3.0L V6 has a well-documented oil consumption/sludge problem that can kill engines if neglected. Transmissions are typically durable, though cooler lines and mounts wear with age.
3.0L V6 Oil Sludge and Excessive Oil Consumption
Common · high severityTypical onset: 80,000-150,000 mi
Symptoms: Blue smoke from exhaust on startup or acceleration, Oil level drops 1+ quart between changes, Check engine light with misfire codes, Rough idle and poor acceleration, Catastrophic engine failure if oil level drops too low
Fix: This is the killer issue on the 3.0L 1MZ-FE. Poor PCV design and marginal oil passages lead to sludge buildup and eventually scored cylinder walls. Catch it early, you're looking at valve cover cleaning and strict 3,000-mile oil change intervals with high-quality synthetic. Miss it, and you're into piston ring replacement (16-20 hours) or full engine rebuild/replacement (20-28 hours). Many owners just swap in a used engine.
Estimated cost: $3,500-7,500
Transmission Oil Cooler Line Leaks
Common · medium severityTypical onset: 100,000-180,000 mi
Symptoms: Pink or red fluid spots under vehicle, Transmission fluid level drops gradually, Burnt transmission smell if fluid runs low, Transmission slipping or delayed engagement if severe
Fix: The steel cooler lines that run to the radiator rust through at the bends and mounting brackets, especially in salt states. Lines themselves are cheap, but you're looking at 2-3 hours labor to replace both lines, flush the system, and refill. Do NOT ignore this—low trans fluid will grenade the U140/U140F transmission.
Estimated cost: $300-600
Transmission Mount Failure
Occasional · medium severityTypical onset: 120,000-200,000 mi
Symptoms: Clunking or banging when shifting from Park to Drive/Reverse, Excessive vibration at idle, Visible sagging of transmission when engine is running, Harsh engagement into gear
Fix: The rear transmission mount (and sometimes engine mounts) deteriorate and the rubber separates from the metal bracket. Front-wheel-drive bias means the trans torques hard on shifts. Replace the trans mount (1.5-2 hours), and inspect engine mounts while you're under there. Often all three need doing at once on high-mileage examples.
Estimated cost: $250-500
Rear Liftgate Latch Failure
Occasional · low severitySymptoms: Liftgate won't latch or stay closed, Have to slam it multiple times to engage, Rattling from rear while driving, Warning light on dash about open liftgate
Fix: The plastic latch mechanism wears out or the striker plate bends from repeated slamming. There was a recall (01V370000) but many vehicles still have the old parts. Replacement latch assembly runs about 1 hour labor. Sometimes adjusting the striker fixes it temporarily, but the latch itself usually needs replacing.
Estimated cost: $150-300
Lower Ball Joint Wear
Common · high severityTypical onset: 80,000-130,000 mi
Symptoms: Clunking noise over bumps from front end, Wandering or loose steering feel, Uneven tire wear on inner edges, Vehicle pulls to one side, Visible play when prying on suspension
Fix: The lower ball joints wear out and develop slop, especially if driven in harsh conditions. On this platform, the ball joint is pressed into the lower control arm, so most shops replace the entire control arm assembly (1.5 hours per side). Do an alignment immediately after. This is a safety item—don't defer it.
Estimated cost: $400-700
Starter Motor Failure
Occasional · medium severityTypical onset: 120,000-180,000 mi
Symptoms: Click-click-click when turning key with no crank, Intermittent no-start, works after multiple attempts, Grinding noise during cranking, Car starts fine when cold, fails when heat-soaked
Fix: The Denso starter develops worn brushes or a bad solenoid. On the V6, it's accessible from underneath in about 1.5-2 hours. The 4-cylinder is easier. Rebuilt starters are cheap and reliable. Heat from the exhaust manifold accelerates failure, so this is more common in hot climates.
Estimated cost: $300-550
Solid buy if it's the 2.4L four-cylinder or a 3.0L V6 with documented frequent oil changes and no smoking; walk away from any high-mileage V6 that burns oil or has sketchy service records.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.